Chair back



FIG. 1 is a front perspective view of a first embodiment of a chair backshowing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a right side elevational view thereof, a left side elevationalview being a mirror image thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a front perspective view of a second embodiment of a chairback showing my new design;

FIG. 8 is a rear perspective view thereof;

FIG. 9 is a front elevational view thereof;

FIG. 10 is a rear elevational view thereof;

FIG. 11 is a right side elevational view thereof, a left sideelevational view being a mirror image thereof;

FIG. 12 is a top plan view thereof;

FIG. 13 is a front perspective view of a third embodiment of a chairback showing my new design;

FIG. 14 is a rear perspective view thereof;

FIG. 15 is a front elevational view thereof;

FIG. 16 is a rear elevational view thereof;

FIG. 17 is a right side elevational view thereof, a left sideelevational view being a mirror image thereof;

FIG. 18 is a top plan view thereof;

FIG. 19 is a front perspective view of a fourth embodiment of a chairback showing my new design;

FIG. 20 is a rear perspective view thereof;

FIG. 21 is a front elevational view thereof;

FIG. 22 is a rear elevational view thereof;

FIG. 23 is a right side elevational view thereof, a left sideelevational view being a mirror image thereof; and,

FIG. 24 is a top plan view thereof.

The broken lines showing is included for the purpose of illustratingenvironment of the design and forms no part of the claimed design.

The ornamental design for a chair back, as shown and described.